Using a sharp chef's or boning knife, trim tenderloin and remove silver skin as for pork tenderloins. Or request a butcher to provide you with a 'peeled and roast-ready tenderloin of beef, silver skin removed.' You don't need it tied, larded, or marinated. You will get a beautiful roast about 15-inches long and 4-inches thick at one end, tapering toward the other end.
Preheat oven to 400° F. Place rack in middle level of oven. Line a 12 x 16-inch rimmed baking sheet with aluminum foil to make cleanup easier. Place a roasting rack on the baking sheet. Rub oil over all sides of meat. Sprinkle with salt and a few grinds of pepper. Place roast on rack, and tuck small 'tail' under so thin end of roast becomes thicker and cooks evenly. Secure with kitchen string.
Place tenderloin in oven and roast until done to your preference-110° F to 120° F for medium rare, 130° F to 140° F for medium, 150° F for medium well. To measure temperature, insert an instant-read thermometer in middle of roast after about 35 minutes, or may take 45 to 50 minutes, depending on your oven and exact weight of roast.
Let roast rest for 5 to 10 minutes to allow juices to set. Place on a carving board and carve across the grain into 1/4 to 1/2-inch slices, beginning at thin end of tenderloin. The last slice or two usually has a little gristle, which isn't visible before carving. You may prefer to reserve it for another use rather than serve to guests.Servings: 2